The invention relates particularly to the field of compact air compressors for medical use, such as for portable oxygen concentrators.
Embodiments of the invention are alternatives to the pump or compressor disclosed in International Application No. PCT/US2013/021394, published 18 Jul. 2013 as No. WO 2013/106810 A1, and U.S. patent application Ser. No. 14/370,707, published Dec. 19, 2014 as No. US 2014/0369873 A1, the entire disclosure of which is hereby incorporated by reference. In that pump or compressor, rotary motion of a shaft is converted to reciprocating motion of a piston rod by a mechanism which includes an eccentric groove in an end plate.
Pumps or compressors for fluid (including air, and gas in general) movement are known for the medical, automotive and beverage industries, as examples. Embodiments of the subject invention are particularly intended for and are useful as compact air compressors for medical use, such as for portable oxygen concentrators.
Piston pumps are well known, and traditionally include a rotating shaft having a concentric attached via a connecting rod to a reciprocating piston, such as are disclosed as “prior art” in publication Nos. WO 2013/106810 A1 and US 2014/0369873 A1.